Green roof systems enable vegetation to grow on a roof of a building or another structure. Some of these systems include a waterproof membrane applied to the surface of the roof. A layer of soil or another growth medium is placed on top of the membrane along with seeds or vegetation, which then grow on the roof. Unfortunately, these systems often require customization for each particular roof design, which can be expensive and time consuming.
Some modular green roof systems are known. For example, U.S. Patent Application Publication No. US 2011/0030274 (Buist) discloses a green roof module for covering a portion of a roofing surface with vegetation. The module includes a tray for containing a growing medium and vegetation, a permeable membrane, and a drainage board. The tray has a biodegradable bottom and a plurality of upwardly extending biodegradable walls about the perimeter of the biodegradable bottom. The biodegradable bottom is configured so that water received within the tray can pass therethrough. The permeable membrane is provided below the biodegradable bottom, and is sized and shaped so as to span the biodegradable bottom and configured to allow water to pass therethrough while inhibiting the growing medium from passing therethrough. The drainage board is provided below the permeable membrane opposite the biodegradable bottom, and has an upper surface for supporting the biodegradable bottom. The drainage board is configured so that at least some of the water passing through the permeable membrane and received on the drainage board will be drained away from the tray. A plurality of the modules can be arranged to cover the surface.
In spite of these known systems, there is a need for improved modular systems for covering roofs and other surfaces with vegetation.